The double bass is the largest and lowest pitched instrument in the string, or 'violin' family, a group of four closely related instruments - the violin, the viola, the 'cello (short for violoncello, hence the apostrophe) and the double bass. It is also known as the string bass or the contrabass though, for simplicity, we will refer to it as the 'bass' for the rest of this guide. Its most striking characteristic is its sheer size - in the line-up of a standard symphony orchestra, it is pretty much the only instrument that is larger than its operator!
The design and dimensions of the other members of the violin family have become largely standardised over the years - not so the bass, which stands apart from its siblings in a number of ways. For a start, there is considerable variety in the shape of basses - some of them have completely flat backs, while others are more curved in the manner of violins and 'cellos. In addition, it is not uncommon to see basses with the top of the back angled forward to make them easier to play - given the vast depth of the instrument's body, anything that allows the players to get closer to the strings and fingerboard is no bad thing. Another major area of variation is the shape of the shoulders - though there are basses with high shoulders along the lines of the rest of the string family, many have shoulders with a pronounced slope which, again, make the instrument rather easier to Play.
Basses also vary in size. Though many modern examples are known as ¾ size and generally tend to be a little smaller than their seventeenth and eighteenth century predecessors, there is no real standard size, and there are even accounts of a thirteen foot bass built as late the middle of the nineteenth century - it needed two musicians to play it!
The strings themselves are another area that can vary from bass to bass. While the rest of the violin family all have four strings each, there are basses around with anything from three strings to six. Admittedly, most have four, but there is no real 'norm'. The bass is also the only instrument in the 'family' to tune each of its strings a 'fourth' (four notes) apart - violins, violas and 'cellos all tune their strings a 'fifth' (five notes) apart.
Despite its size, the bass is not a loud instrument, in fact many people are surprised just how gently voiced it is when heard in isolation. Consequently, it is not uncommon to see twelve or more basses in a full symphony orchestra, particularly for larger scale Romantic repertoire. It is generally accepted that the violin and 'cello are proportionally very similar in terms of the ratio between their size and pitch. The viola and bass by comparison though, would both need to be un-playably large to maintain this ratio. However, far from being a fault, this is what gives them their gentle, mellow character.
In terms of repertoire, the bass has tended to be left rather on the back burner in the field of classical music. Until the end of the Eighteenth Century, no-one really considered it a melodic instrument until two Italians changed all that: Domenico Dragonetti and Giovanni Bottesini - who between them straddled most of the nineteenth century - were the first real bass virtuosi, and they forced both composers and audiences to re-assess the instrument. All the subsequent bass solo repertoire stems from the sea-change brought about by these two men. Even so, most of this repertoire is still relatively unknown to the modern concert-hall audience. However, if we move into the world of jazz and blues, the tables are comprehensively turned. Here, the bass is an absolute essential - the only string instrument to make it into the standard line-up. In this field, it tends to be plucked 'pizzicato', rather than bowed, as this enables the instrument to be heard better, and also gives it a more percussive sound which drives the music along in partnership with the drums. Consequently, a whole repertoire of pizzicato styles has grown up in this genre, which has also given the bass much more of a solo spotlight alongside its traditional bass-line duties.